<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Cache
 * @subpackage Zend_Cache_Backend
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Xcache.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Cache_Backend_Interface
 */
require_once 'Zend/Cache/Backend/Interface.php';
/**
 *
 * @see Zend_Cache_Backend
 */
require_once 'Zend/Cache/Backend.php';

/**
 *
 * @package Zend_Cache
 * @subpackage Zend_Cache_Backend
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Cache_Backend_Xcache extends Zend_Cache_Backend implements Zend_Cache_Backend_Interface {

    /**
     * Log message
     */
    const TAGS_UNSUPPORTED_BY_CLEAN_OF_XCACHE_BACKEND = 'Zend_Cache_Backend_Xcache::clean() : tags are unsupported by the Xcache backend';

    const TAGS_UNSUPPORTED_BY_SAVE_OF_XCACHE_BACKEND = 'Zend_Cache_Backend_Xcache::save() : tags are unsupported by the Xcache backend';

    /**
     * Available options
     * =====> (string) user :
     * xcache.admin.user (necessary for the clean() method)
     * =====> (string) password :
     * xcache.admin.pass (clear, not MD5) (necessary for the clean() method)
     * @var array available options
     */
    protected $_options = array('user' => null, 'password' => null);

    /**
     * Constructor
     * @param array $options associative array of options
     * @throws Zend_Cache_Exception
     * @return void
     */
    public function __construct (array $options = array()) {
        if ( ! extension_loaded ('xcache')) {
            Zend_Cache::throwException ('The xcache extension must be loaded for using this backend !');
        }
        parent::__construct ($options);
    }

    /**
     * Test if a cache is available for the given id and (if yes) return it (false else)
     * WARNING $doNotTestCacheValidity=true is unsupported by the Xcache backend
     * @param string $id cache id
     * @param boolean $doNotTestCacheValidity if set to true, the cache validity won't be tested
     * @return string cached datas (or false)
     */
    public function load ($id, $doNotTestCacheValidity = false) {
        if ($doNotTestCacheValidity) {
            $this -> _log ("Zend_Cache_Backend_Xcache::load() : \$doNotTestCacheValidity=true is unsupported by the Xcache backend");
        }
        $tmp = xcache_get ($id);
        if (is_array ($tmp)) {
            return $tmp[0];
        }
        return false;
    }

    /**
     * Test if a cache is available or not (for the given id)
     * @param string $id cache id
     * @return mixed false (a cache is not available) or "last modified" timestamp (int) of the available cache record
     */
    public function test ($id) {
        if (xcache_isset ($id)) {
            $tmp = xcache_get ($id);
            if (is_array ($tmp)) {
                return $tmp[1];
            }
        }
        return false;
    }

    /**
     * Save some string datas into a cache record
     * Note : $data is always "string" (serialization is done by the
     * core not by the backend)
     * @param string $data datas to cache
     * @param string $id cache id
     * @param array $tags array of strings, the cache record will be tagged by each string entry
     * @param int $specificLifetime if != false, set a specific lifetime for this cache record (null => infinite lifetime)
     * @return boolean true if no problem
     */
    public function save ($data, $id, $tags = array(), $specificLifetime = false) {
        $lifetime = $this -> getLifetime ($specificLifetime);
        $result = xcache_set ($id, array($data, time ()), $lifetime);
        if (count ($tags) > 0) {
            $this -> _log (self::TAGS_UNSUPPORTED_BY_SAVE_OF_XCACHE_BACKEND);
        }
        return $result;
    }

    /**
     * Remove a cache record
     * @param string $id cache id
     * @return boolean true if no problem
     */
    public function remove ($id) {
        return xcache_unset ($id);
    }

    /**
     * Clean some cache records
     * Available modes are :
     * 'all' (default) => remove all cache entries ($tags is not used)
     * 'old' => unsupported
     * 'matchingTag' => unsupported
     * 'notMatchingTag' => unsupported
     * 'matchingAnyTag' => unsupported
     * @param string $mode clean mode
     * @param array $tags array of tags
     * @throws Zend_Cache_Exception
     * @return boolean true if no problem
     */
    public function clean ($mode = Zend_Cache::CLEANING_MODE_ALL, $tags = array()) {
        switch ($mode) {
            case Zend_Cache::CLEANING_MODE_ALL :
                
                // Necessary because xcache_clear_cache() need basic authentification
                $backup = array();
                if (isset ($_SERVER['PHP_AUTH_USER'])) {
                    $backup['PHP_AUTH_USER'] = $_SERVER['PHP_AUTH_USER'];
                }
                if (isset ($_SERVER['PHP_AUTH_PW'])) {
                    $backup['PHP_AUTH_PW'] = $_SERVER['PHP_AUTH_PW'];
                }
                if ($this -> _options['user']) {
                    $_SERVER['PHP_AUTH_USER'] = $this -> _options['user'];
                }
                if ($this -> _options['password']) {
                    $_SERVER['PHP_AUTH_PW'] = $this -> _options['password'];
                }
                $cnt = xcache_count (XC_TYPE_VAR);
                for ($i = 0; $i < $cnt; $i ++ ) {
                    xcache_clear_cache (XC_TYPE_VAR, $i);
                }
                if (isset ($backup['PHP_AUTH_USER'])) {
                    $_SERVER['PHP_AUTH_USER'] = $backup['PHP_AUTH_USER'];
                    $_SERVER['PHP_AUTH_PW'] = $backup['PHP_AUTH_PW'];
                }
                return true;
                break;
            case Zend_Cache::CLEANING_MODE_OLD :
                $this -> _log ("Zend_Cache_Backend_Xcache::clean() : CLEANING_MODE_OLD is unsupported by the Xcache backend");
                break;
            case Zend_Cache::CLEANING_MODE_MATCHING_TAG :
            case Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG :
            case Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG :
                $this -> _log (self::TAGS_UNSUPPORTED_BY_CLEAN_OF_XCACHE_BACKEND);
                break;
            default :
                Zend_Cache::throwException ('Invalid mode for clean() method');
                break;
        }
    }

    /**
     * Return true if the automatic cleaning is available for the backend
     * @return boolean
     */
    public function isAutomaticCleaningAvailable () {
        return false;
    }

}
